1. Field of the Invention
The present invention relates to wireless communications. More particularly, the present invention relates to a method and an apparatus for controlling network access of a User Equipment (UE) based on the network's load and time tolerance (delay tolerance).
2. Description of the Related Art
When a Machine Type Communication (MTC) or a Machine To Machine (M2M) device, or a User Equipment (UE) and a normal UE attempt to access a network simultaneously, there is a need to restrict the device's access to the network based on the network load in a wireless communication system. That is, if the MTC device has the time tolerant feature, the wireless communication system should restrict the MTC device's access to the network and/or the sending of data towards the MTC device and should limit the amount of data that the MTC device can transfer.
When restricting the service to the MTC device, the network load configuration values are used as thresholds to start the service restriction according to the subscriptions of the MTC device. For example, in a case of the MTC device (e.g., metering device) which reports measurement results periodically, the network load configuration value for the service restriction to the subscription having the time tolerance level which requires reporting of the entire utilization of a day, should differ from the network load configuration value for the service restriction to the subscription having the time tolerance level which requires reporting at a time interval set under contract of the dynamic billing policy.
In the related art, however, it is impossible to set the network load configuration values for the network use restrictions of the MTC device to different values individually according to the time tolerant levels of the subscriptions. Accordingly, it is difficult to expect good efficiency of the access barring which is performed, in the wireless communication system of the related art, to restrict the network access of the MTC device when the network congestion reaches a predefined level. That is, the network access control method of the related art has a drawback in that it is impossible to set the time tolerant level per MTC device or per subscription of the MTC device.
Therefore, a need exists for a method and an apparatus for controlling network access of MTC devices with time tolerant feature in a wireless communication system that is capable of restricting the MTC devices' network access, for sending of data towards MTC devices, and for limiting the amount data that the MTC device can transfer.